Ringing-off device for telephones



(No Model.)

A. GRIFFITH 8v H. A. BURBANK.

EINGING OEE DEVICE EOE TELEPHONES.

No. 394,173. atentedDgo. 11, 1888..

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M a l Q/ @51A mm1/MMM UNTTED STATES AMENZO GRIFFITII, OF SPRINGFIELD,

PATENT OEFicE.

AND HENRY A. BIIRISANK, OF \VEST- FIELD, MASSACHUSETTS.

SPECIFICATION forming part of Letters Patent N o. 394,173, dated December 11, 1888. Application filed August 2, 1888. Serial No. 281,739. (No model.)

To all whom it 71mg concern:

Beit kn own that we, AMENZO GRIFFITH and HENRY A. BURBANK, citizens of the United States, residing, respectively, at Springfield and lVestIield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Ringing-Oft' Devices for Telephones, of which the following' is a specification.

This invention relates to telephone callboxes, and pertains to improvements therein, having for their object the provision ot' devices connected with or attached thereto, whereby the instrument automatically causes i 5 an alarm-bell to be rung in the central oiiice when the parts thereof, after a conversation, are returned to their normal positions, said alarm being termed, ordinarily, ring off, and thereby the office is told that the use of the instrument from which said alarm is given has ceased.

In the drawings forming part of thi specification, Figure l is a front elevation of an ordinaryT telephone box having the cover partly broken away, and having automatic ringing-olf devices applied thereto embodying our invention, said figure illustrating, also, an electric circuit and an alarm-bell in connection with said telephone-box. Figs. 2, and 4 illustrate detail parts of the improvements, as hereinafter fully described.

In the drawings, A indicates the telephone call-box of the ordinary well-known construction, of which B is the metallic lever, on the outer or free end ofwhich the usual receiver is hung when the instrument is not in use. Said lever is pivoted by one end to the inner side of the box, as shown, and its free end projects through the opposite side of the box, 4o and is bifurcated or otherwise conveniently formed to provide for hanging said receiver thereon, as aforesaid. A spring, 2, is attached to the box and to the said lever B, to swing its free end upward to the position shown in Fig. I, when the receiver is taken olf from the lever by a person wishing to use the instrument. The replacing of the receiver on said lever swings its free end downward, or to its normal posit-ion,when the instrument is at rest. Lever B is connected by suitable conductors, ce, through the post 3, with any suitable electric generator, a local battery, i, being indicated as such in Fig. l. On lever B is firmly secured, by a suitable metallic connection, a metal hook, 5, which, by the said vibratory motion ot said lever, is given a reciprocating vertical motion.

A iiexible metallic arm, (l, is attached by one end to the inner side of the box A, and extends therefrom in a line with the lever B, 6o its free end reaching somewhat past the end of the hook 5, as shown. One side of the free end of said lever has its metallic side exposed to contact with the end of said hook when the latter moves downward past it, the 6 5 arm being so set, as shown in Figs. 2, 3, and i, that it presents its uncovered side at an incline to the end of said hook, and thereby the latter, in moving downward from the position shown in Figs. l and 2 to that shown in Fig. 7o 3, will have a sliding contact with said arm, the end of the latter springing back to the position shown in Fig. 3 after the hook 5 leaves it. Figs. 2 and 3 are sectional views of said lever B, hook 5, and flexible arm G, on the line ai a?, Fig. l, showing said lever and hook in the two above-referred-to positions. The said arm 6 has applied to one side thereof a non-conducting substance, 7such as hard rubber or similar material-so that when the 8o lever B swings upward from the position shown in Fig. 3 to that shown in Fig. 2 the hook 5 shall slide on said non-conductor and have no electrical contact with the arm.

Fig. 4 illustrates the arm 6 made a little 85 wider than those shown in Figs. 2 and 3, and having a longitudinal slot or a perforation in it, through which a portion of the non-conducting material 7 protrudes, as shown, leaving metallic surfaces d d each side of the cen- 9o Jorally-disposed material 7, with which the end of the hook 5, in its said downward motion, is brought successively into contact. Theiixed end of the arm has an electric connection with any convenient part of the line 8, leading to the central ot'iice, by a conductor, 9, and any suitable alarm-bell at said office is connected in said line, one end of the latter being grounded, as shown, and one pole of said battery 4 being also grounded, an electric circuit 10o is formed, in which are included the hook 5, the flexible arm 6, and said alarm-bell.

The operation of our improvements is as follows: The positions of the lever B and the hook 5 before said receiver is taken from the protruding end of said lever, as aforesaid, are shown in Fig. 3. Upon removing the receiver spring 2 swings the free end of lever B upward, as described, and in its ascent the end of hook 5 strikes the insulated side 7 of said lever, springing the latter slightly, and passes by it. The said arm then springs back to the position shown in Fig. 2, with its metallic side directly under the end of hook 5. lhen the person has concluded the telephone conversation and rehangs the receiver on the end of lever B, thereby imparting to it a downwardly-swinging movement, the end of hook 5 is made to move against the metallic side of arm 6, making an electric connection therewith, closing the aforesaid electric circuit and causing the said alarmebell to be rung, which announces to the central office automatically that the use of the instrument has ceased.

The provision of the above-described improvements, whereby said alarm-bell is rung by hanging on the receiver, obviates the necessity of ringing in a special notice to the office when the person has ceased to use the instrument, and prevents the frequent neglect of persons to give such notice, to the great convenience of the central oflice.

The construction described of the hook' 5 and the arm 6, by the up-and-down movement of the hook, whether as shown in Figs. 2 and 3 or in Fig. 1, provides for a make-and-break connection in the said electrical circuit of which they form a part; but the construction shown in Fig. 4 differs slightly from the others named, in that it provides for two separate contacts of said hook with the metallic f ace of the arm 6 during its downward movement,

thereby causing the said alarm-bell to ring twice instead of once, as in the arm-construction shown in Figs. 2 and 3.

lt is obvious that in lieu of an alarm-bell signal, indicators of other descriptions maybe employed, such as the well-known dropping numbered disks, the same, however, being merely equivalents of the bell, but may in some instances be preferably employed.

Vv'hat we claim as our invention isln an automatic ringing-off apparatus for telephone systems, in combination, the callboX, the ieXible arm 6, supported therein, having a portion thereof in an inclined plane, one side thereofbeing formed of material for an electrical conductor, and the other side thereof being formed of material for a nonconductor, the swinging receiver holder-arm provided with the hook 5, so located on said arm that when the latter is in its normal depressed position or in its uppermost position said hook will be out of contact with said arm, but whereby in its passage from its normal to its upper position said hook will pass into and out of contact with the non-conductor side of said flexible arm, and on the return movement of said arm said hook will pass into and out of contact with the conductor side of said arm, the central-oftice signal-indicator, the lineconnection between same and said flexible arm, a local electrical generator and a grounded conductor leading therefrom, and a connection between same and said holderarm hook, substantially as and for the purpose described.

AMENZO GRIFFITH. HENRY A. BURBANK. Witnesses:

WM. S. BELLows, H. A. CHAPIN. 

